Operational amplifiers (Op-amps) are often used in signal processing applications such as filter circuits, amplifier circuits etc. Referring now to FIGS. 1A-1C, an op-amp 10 has an inverting input 12, a non-inverting input 14, and an output 16. Op-amps may be used as inverters. In FIG. 1B, an electrical schematic of an op-amp 20 in a typical inverter configuration is shown. In an inverter, an input signal is applied to the inverting input of the op-amp. A phase of the output of the inverter is 180 degrees out of phase with respect to the input to the inverter. Resistors R1 and R2 determine a gain of the inverter 20. For example, an inverter is called a unity gain amplifier when R1=R2. In FIG. 1C, a symbol 24 used to represent an inverter in a circuit diagram is shown.
Referring now to FIG. 1D, a frequency response of an amplifier shows a graph of the gain of the amplifier as a function of the frequency of the input signal. A range of input signal frequencies that an amplifier can amplify at or above a predetermined gain is called the bandwidth of the amplifier. The gain bandwidth product of an op-amp is typically constant. Thus, the bandwidth of an op-amp is inversely proportional to the gain of the op-amp.